// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: http://codemirror.net/LICENSE

(function(mod) {
  if (typeof exports == 'object' && typeof module == 'object')
    // CommonJS
    mod(require('../../lib/codemirror'));
  else if (typeof define == 'function' && define.amd)
    // AMD
    define(['../../lib/codemirror'], mod);
  // Plain browser env
  else mod(CodeMirror);
})(function(CodeMirror) {
  'use strict';

  CodeMirror.defineMode('ebnf', function(config) {
    var commentType = { slash: 0, parenthesis: 1 };
    var stateType = { comment: 0, _string: 1, characterClass: 2 };
    var bracesMode = null;

    if (config.bracesMode)
      bracesMode = CodeMirror.getMode(config, config.bracesMode);

    return {
      startState: function() {
        return {
          stringType: null,
          commentType: null,
          braced: 0,
          lhs: true,
          localState: null,
          stack: [],
          inDefinition: false,
        };
      },
      token: function(stream, state) {
        if (!stream) return;

        //check for state changes
        if (state.stack.length === 0) {
          //strings
          if (stream.peek() == '"' || stream.peek() == "'") {
            state.stringType = stream.peek();
            stream.next(); // Skip quote
            state.stack.unshift(stateType._string);
          } else if (stream.match(/^\/\*/)) {
            //comments starting with /*
            state.stack.unshift(stateType.comment);
            state.commentType = commentType.slash;
          } else if (stream.match(/^\(\*/)) {
            //comments starting with (*
            state.stack.unshift(stateType.comment);
            state.commentType = commentType.parenthesis;
          }
        }

        //return state
        //stack has
        switch (state.stack[0]) {
          case stateType._string:
            while (state.stack[0] === stateType._string && !stream.eol()) {
              if (stream.peek() === state.stringType) {
                stream.next(); // Skip quote
                state.stack.shift(); // Clear flag
              } else if (stream.peek() === '\\') {
                stream.next();
                stream.next();
              } else {
                stream.match(/^.[^\\\"\']*/);
              }
            }
            return state.lhs ? 'property string' : 'string'; // Token style

          case stateType.comment:
            while (state.stack[0] === stateType.comment && !stream.eol()) {
              if (
                state.commentType === commentType.slash &&
                stream.match(/\*\//)
              ) {
                state.stack.shift(); // Clear flag
                state.commentType = null;
              } else if (
                state.commentType === commentType.parenthesis &&
                stream.match(/\*\)/)
              ) {
                state.stack.shift(); // Clear flag
                state.commentType = null;
              } else {
                stream.match(/^.[^\*]*/);
              }
            }
            return 'comment';

          case stateType.characterClass:
            while (
              state.stack[0] === stateType.characterClass &&
              !stream.eol()
            ) {
              if (!(stream.match(/^[^\]\\]+/) || stream.match(/^\\./))) {
                state.stack.shift();
              }
            }
            return 'operator';
        }

        var peek = stream.peek();

        if (bracesMode !== null && (state.braced || peek === '{')) {
          if (state.localState === null)
            state.localState = CodeMirror.startState(bracesMode);

          var token = bracesMode.token(stream, state.localState),
            text = stream.current();

          if (!token) {
            for (var i = 0; i < text.length; i++) {
              if (text[i] === '{') {
                if (state.braced === 0) {
                  token = 'matchingbracket';
                }
                state.braced++;
              } else if (text[i] === '}') {
                state.braced--;
                if (state.braced === 0) {
                  token = 'matchingbracket';
                }
              }
            }
          }
          return token;
        }

        //no stack
        switch (peek) {
          case '[':
            stream.next();
            state.stack.unshift(stateType.characterClass);
            return 'bracket';
          case ':':
          case '|':
          case ';':
            stream.next();
            return 'operator';
          case '%':
            if (stream.match('%%')) {
              return 'header';
            } else if (stream.match(/[%][A-Za-z]+/)) {
              return 'keyword';
            } else if (stream.match(/[%][}]/)) {
              return 'matchingbracket';
            }
            break;
          case '/':
            if (stream.match(/[\/][A-Za-z]+/)) {
              return 'keyword';
            }
          case '\\':
            if (stream.match(/[\][a-z]+/)) {
              return 'string-2';
            }
          case '.':
            if (stream.match('.')) {
              return 'atom';
            }
          case '*':
          case '-':
          case '+':
          case '^':
            if (stream.match(peek)) {
              return 'atom';
            }
          case '$':
            if (stream.match('$$')) {
              return 'builtin';
            } else if (stream.match(/[$][0-9]+/)) {
              return 'variable-3';
            }
          case '<':
            if (stream.match(/<<[a-zA-Z_]+>>/)) {
              return 'builtin';
            }
        }

        if (stream.match(/^\/\//)) {
          stream.skipToEnd();
          return 'comment';
        } else if (stream.match(/return/)) {
          return 'operator';
        } else if (stream.match(/^[a-zA-Z_][a-zA-Z0-9_]*/)) {
          if (stream.match(/(?=[\(.])/)) {
            return 'variable';
          } else if (stream.match(/(?=[\s\n]*[:=])/)) {
            return 'def';
          }
          return 'variable-2';
        } else if (['[', ']', '(', ')'].indexOf(stream.peek()) != -1) {
          stream.next();
          return 'bracket';
        } else if (!stream.eatSpace()) {
          stream.next();
        }
        return null;
      },
    };
  });

  CodeMirror.defineMIME('text/x-ebnf', 'ebnf');
});
